A CCTV system is a closed-circuit television installation: cameras, cabling or network links, a recorder and viewing equipment, kept on a private path rather than broadcast publicly. The term predates IP video but still covers both analog and network systems, and it is best understood as the camera layer of an electronic security system.
Closed circuit once meant a coaxial loop that only the site could see. The phrase survives even though the signal now travels over the same network as everything else.
What closes the circuit
The signal path stays inside the site’s own infrastructure: camera to recorder to a monitor or a client. Nothing is transmitted for public reception, though remote access over the internet has blurred the practical boundary. The recorder remains the point where footage is kept and exported.
CCTV and IP video today
Modern installations use network cameras, Power over Ethernet and digital recorders, so the older term now describes the function rather than the technology. Analog and IP systems can coexist through a hybrid recorder. What matters to the user is coverage, image quality and how easily footage is retrieved.